Most of the time, the attacking force would send a messenger to the lord of the castle and give notice of their intentions to attack. This notice allowed the castle to surrender. Sometimes the lord surrendered, but most often the castle was restocked and made ready for the siege. They would restock themselves with food, supplies and drink, and add men to the garrison.

There were three ways to take a castle. The first is not to attack the castle at all - just avoid the castle altogether and seize the lands around it. The second is direct assault, or laying siege to the castle. The last is besieging.

Here is an account of a siege. Stone throwing mangonels attack the towers and walls every day. The walls of the castles would hopefully be breached, and towers damaged. The enemy erects wooden towers called belfries, taller than the castle towers, to conceal and enable bow men to shoot arrows down into the castle. While this is going on, miners would be tunneling under the walls and towers of the castle in preparation to collapse them.

To counter the mining, anti-mining tunnels could be dug by the castle soldiers, which insured a ferocious hand-to-hand battle underground. Inside the castle, the guards would place a pot of water near the castle towers and walls. When the water rippled, they would know enemy miners were at work underneath them. Since some castles were defended with as few as 14 soldiers, you can imagine how busy they would be at this point!

The barbican is next assaulted and taken, with a loss of men on both sides. Then the bailey is attacked, and more men killed. Animals and some supplies would be captured. The auxiliary buildings containing hay and grain for the castle are burned. By now, miners have succeeded in collapsing a wall of the castle. The attackers have broken through and seized the inner bailey. More men on both sides would be lost in this phase of the attack.

By this time, the castle defenders would have retreated to the keep. Miners would now be setting fire to the mine tunnel under the keep. Smoke and fire are rising into the keep, and cracks appearing in the thick walls. The defenders of the castle are forced to surrender as the castle falls to the enemy.

The third method, called besieging, would require the enemy to wait and starve the castle garrison into surrender. This method was preferred by an attacking side. Some sieges of this type would last from six months to a year. Sometimes, the enemy would hurl dead animals into the castle grounds in hopes of spreading diseases. And, sometimes the lord of the castle would toss dead animals outside his castle, to convince the enemy they had enough supplies to carry on a siege for months.